


Castiel's Kitten

by omegadeanlovesalphacas



Category: Supernatural
Genre: (Dean's brainwashed but happy), (er uh vet kink?), Alpha Castiel/Omega Dean Winchester, Alpha/Beta/Omega Dynamics, Castration, Claiming, Cock Cages, Collars, Fluff, Kitten Dean, Knotting, Leashes, M/M, Medical Kink, Oral Knotting, Orgasm Denial, Pet Play, Public Nudity, Size Difference, Size Kink, Slightly painful first time sex, Underage Dean, Virgin Dean, alpha!Castiel, dubcon, omega!dean, store bought Dean
Language: English
Status: Completed
Published: 2017-05-03
Updated: 2017-05-03
Packaged: 2018-10-27 03:40:33
Rating: Explicit
Warnings: Underage
Chapters: 2
Words: 4,713
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10800945
Author URL: https://archiveofourown.org/users/omegadeanlovesalphacas/pseuds/omegadeanlovesalphacas
Summary: Castiel finally buys the kitten!omega of his dreams and maybe makes an Instagram account.





	1. Chapter 1

**Author's Note:**

> Warning! This is an Alpha/omega kink prompt fill. Expect more porn than plot, and lots of power imbalance between Cas and Dean. Mind the warnings and kinks in the tags.
> 
> WARNING!! Chapter two includes castration as a kink. Chapter one doesn’t even mention it, and it stands alone, so you can read just the first chapter if that’s not your jam. [Click here if you’re new to castration kink and want to read my write up explaining it.](http://omegadeanlovesalphacas.tumblr.com/castrationkink)

Castiel just couldn’t help himself. It was Saturday morning and he found himself in OmegaPaws, his towns local omega pet shop. He was looking at the omega kitten supplies again, in particular the ear and tail sets. He already had a whole collection of supplies at home, he’d been wanting an omega kitten for a while now, he was just waiting for the right time to finally buy one.

He finally had a good enough job to afford the high price tag, and since he’d just turned thirty he figured an omega was the perfect birthday gift.

A bubbly young sales girl appeared at his side. “Aren’t those cute?” she said. She was a beta, with long brown hair and an infectious smile. According to her name tag her name was Emily. “We just got a new shipment of omega kittens, have you seen them? They’re adorable.”

Castiel brightened. The store hadn’t had omega kittens in stock for weeks, he’d been hoping they would get more. “No! Can I see them?”

“Yeah, of course!” The girl said, leading Castiel through the store to the back. Along the back wall was a bank of omega sized cages, allowing interested alphas to view the omega pets with ease. Each cage had sturdy bars and a padlock, to protect the inventory.

There were a whole variety of male and female omega pets: bunnies, puppies, and kittens. Each omega was naked, except for basic tail plug and ears. The omega kittens were all down to the right, and the girl took Castiel to see them.

Castiel was immediately drawn to one of the kittens, he was a particularly petite male omega, with light brown hair and green eyes. He wore a simple pair of black ears and tail, and he was playfully batting at a ball, bouncing it off the wall. He smelled _perfect_.

“Tell me about this one,” Castiel said, stepping up to the cage bars.

“This is Dean, he’s 15 years old,” Emily said. “He was bred and raised at SubMission Ranch. They sell a variety of omegas, he was chosen for pet training based on his petite size, cuddly nature, and strong sex drive. Dean is still a virgin, but he’s very eager for a good home and an alpha who will knot him regularly.”

Dean chose that moment to crawl to the cage door, and he looked up at Castiel through the bars with curious eyes. He took a deep breath, scenting the alpha, then let out a little meow. He turned sideways and rubbed his whole body up against the bars, then turned around to present his perfect ass. His black tail was flopped up over his back, letting Castiel get a good look at the omega’s hole gripping tight around the plug. Dean spread his legs a little and arched his back, shifting back and forth on his knees in invitation.

The sales girl laughed. “I think he likes you!”

“I’ll take him,” Castiel said quickly, trying to will away his growing erection. He’d be knotting that kitten soon enough. He didn’t even care about the price, whatever it was, he would pay it.

The girl brightened. “That’s great!” She reached up above the cage and pulled down a little sold sign, hanging it from the bars. “I’ll help you pick out whatever you need for him, then we’ll come back for him after he’s paid for.”

Castiel let the girl guide him through his purchases, explaining he already had food and water bowls, a lot of toys, and a bed. She helped him pick out a couple more beds, a crate, and a cock cage. Then she took him back to the ears and tails where she’d originally found him.

“Now, he comes with his basic black ears and tail, but I saw you eying the nicer sets,” she said, gesturing to the wall of options. “I’d suggest a set with a tail plug and a tail belt. It’s nice to have a tail that leaves his hole available.”

Castiel agreed, he wanted to be able to tug on a tail while he knotted his kitten. “I think this set suits him,” he said, picking up a light brown tabby set that matched the color of Dean’s hair.

“Perfect!” The sales girl then guided him to the collars and leashes. “I’m sure you know that omega pets are required to be leashed in public,” she said. “I’d recommend leather, it’s the most durable.”

Castiel’s eyes were immediately drawn to a dark green leather collar and leash. “If I remember correctly, this will compliment his eyes.”

With everything he needed in hand, Castiel headed up front to pay for it all. On a whim he added an ID tag for the collar, since they had the engraving machine that could make it on the spot.

It read “Castiel’s Kitten.” It was perfect.

Finally the sales girl took him back to collect Dean, and Castiel’s heart was racing as she pulled out a key and unlocked the cage. The omega immediately came forward for pets, looking up at Castiel eagerly. Castiel grinned and reached out to run a hand through the omega’s soft hair.

“Hi kitten,” he said, smiling. “I’m your new owner.”

Dean little out a little meow and started to purr, leaning into Castiel’s hand.

Castiel wanted to get him home. _Now._

“Let’s get him collared and then you’re ready to go,” the girl said, removing the tags from the collar and unbuckling it before handing it to Castiel. “He’ll walk on command, it’s much more convenient in public, but he will stay on hands and knees unless he’s told otherwise.”

Castiel buckled the collar around the omega’s neck, pleased by the snap of the lock securing it in place. He loved how the ID tag looked hanging down from the collar.

“Okay, walk,” Castiel ordered, tugging gently on Dean’s leash. The omega kitten came out of his cage eagerly, getting up on two feet as ordered. “Good kitten,” Castiel praised.

“All his paperwork is in the bag,” the girl said, still holding most of Castiel’s purchases. “It has a list of all the commands he already knows. And he comes with free training classes here, so I definitely recommend you bring him back to take advantage of that.”

Castiel nodded, he would do that, but right now he just wanted to get his kitten home.

* * *

Dean was good for the car ride, sitting like a proper omega kitten in the front seat, but still buckled in. When they got home Castiel decided to leave most of the supplies in the car to worry about later, picking up just Dean’s leash and the bag with the ears and tail.

“Come on, kitten,” Castiel said, leading Dean inside.

As soon as they crossed the threshold, Dean dropped down to his hands and knees without being told, looking up at Castiel.

“Good kitten,” Castiel said, realizing that must be part of his training. He reached down and unclipped the leash, hanging it up by the front door. “Come on,” he said, looking to see if Dean would follow him as he moved toward the bedroom.

Dean did, scampering after him and meowing.

Castiel grinned, leading his knew kitten up the stairs and into the bedroom. “Up,” he said, patting the bed.

Dean climbed up on the bed and started to stomp around in a circle, stopping to present himself to Castiel again.

Castiel didn’t need to be asked twice, but he wanted to do one thing first. He pulled out the new tabby ears and the tail belt. He reached for Dean’s little black ears and swapped them for the tabby ears. Dean just watched with curiosity. Then he reached for the base of the tail plug and slowly tugged it free, enjoying the way Dean let out a little needy yowl in response.

Castiel stopped to admire the way Dean’s hole gaped open in invitation for a moment before it started to wink closed. Slick was already running down the inside of the omega’s legs, it had clearly been held back by the plug.

Castiel pulled the tags off the tail belt. It had a brown leather belt that went around the omega’s waist, then thinner leather straps that went between his legs to hold it in place. Once Castiel had it on, the tabby tail was perfectly flush with Dean’s tailbone. It could either hang down to cover the omega’s hole or be flipped up over his back, which was how Castiel left it.

Castiel stepped back from the bed and started to undress, watching how Dean continued to arch his back and spread his legs, begging to be filled up.

He was going to do just that.

As soon as Castiel was naked he climbed up on the bed behind Dean and grabbed his little omega kitty by the tail, yanking him backward. He was pleased to feel the tail was strong, clearly designed with this in mind.

With no more patience left, Castiel lined his hard cock up to Dean’s entrance and slowly pushed inside, and he groaned as he was swallowed up. The omega was so small and it seemed impossible that his virgin hole could take the alpha’s cock, but despite the dizzying tightness he still sunk into the slick heat.

Dean let out a yowling cry as Castiel’s huge cock stretched him open and pushed in deep, but he still dropped his face to the bed to push his ass up higher, submitting to his alpha. His pained cries were quickly mixed with pleasured moans that somehow still sounded like a kitten, and he squirmed under the alpha as his body adapted to being properly filled for the first time.

Castiel was trying to go easy at first, knowing this was the first time this omega had more than a plug inside him, but he couldn’t hold out much longer. He started to move, steadily at first, then faster. His hips started to slap against the omega’s ass with each sharp thrust, driving in deeper with each pass.

Under him Dean’s little body shook with the force of each thrust, and it wasn’t long before he was coming hard across the bed with another yowl.

Castiel didn’t last very much longer, his knot was growing fast and filling the omega more with each stroke. Finally with a groan and a final slamming thrust his knot drove fully into the omega and he came hard, knot tying in place and seed spilling deep inside his kitten.

Dean panted and squirmed as he was knotted for the first time, a look of shock and revelation painted across his face. He let out a breathless little meow and pushed back against the knot, quivering as his hole stretched to accept the intrusion.

Castiel collapsed overtop of Dean, his larger body covering the omega’s smaller one, and he bit down hard on the back of Dean’s neck, making the omega cry out at the mix of pleasure and pain. His kitten was now fully and completely _his._

With a satisfied groan Castiel laid over on his side, pulling Dean with him. His kitten started to purr and cuddle back into him, his channel clenching down around the knot filling him. The scent of happy omega was rolling off him in waves and Dean let out a little mewling moan every time Castiel’s knot shifted inside him.

Castiel eyed the mess on the bed. “I’m glad she sold me that cock cage, we can’t have this every day,” he said. He knew it was recommended to limit kitten orgasms anyway, it was the best way to keep them obedient and eager.

He reached over to the bag and was pleased to see the silver cock cage was one of the only other items in the bag. Sitting up half way he leaned over Dean and carefully fitted it in place. He then laid back down to enjoy the rest of his knot with his new kitten in his arms.

* * *

Castiel spent the rest of the day playing with his new kitten. Every time his knot would go down Dean would beg for another, so that by dinner time he’d lost track of how many times he’d knotted him. Finally content to take a break, Castiel swapped Dean’s tail belt for the tail plug, safely keeping his new omega pet full of his seed.

“Come on, kitten, time for dinner,” Castiel said, climbing out of bed and pulling on a pair of pajama pants.

Dean let out a tired little meow, but climbed out of bed and followed him out of the bedroom on his hands and knees.

Castiel grinned and headed for the kitchen. He already had a bed and two bowls on the floor in the corner, and he picked up one of the bowls to fill it with water before setting it back down.

Without hesitation, Dean crawled over and dropped his head to drink from the bowl, drinking quite greedily until his thirst was quenched. Then he turned and crawled over to the bed, flopping down on it. Dean rolled over on his back and sprawled just like a happy cat, with his hands tucked up under his chin, and his knees up and spread open. In this pose you could see everything from his ears and ID tag to his cock cage and tail plug between his legs. His eyes were closed and he looked very content, especially with the telltale roundness of his belly and the little bit of come leaking out around the plug. He realized his kitten was actually asleep already, all worn out from so much play.

On a whim Castiel pulled out his phone and took a picture. Dean looked so adorable and debauched, and it reminded him of all the omega pet accounts he followed on Instagram. It was were he’d gotten the idea of an omega kitten in the first place, admiring all the cute and sexy pictures of other alphas’ pets.

Castiel himself never even posted anything to Instagram, but maybe now that he had something worth posting…

Logging into his account on his phone, Castiel went into his settings and changed the name of his account to ‘CastielsKitten’ and changed the bio to a dedicated omega kitten account. He then posted the picture he’d just taken, pausing to write a caption.

> Meet my new kitten, Instagram! Follow for more #contentkitten #pluggedfullofmilk #collaredkitten #omegakitten #okitsofinstagram

He hit ‘share’ and set the phone down on the kitchen counter while he got started on dinner. The whole time he was cooking his phone continually buzzed with notifications as people liked his picture and followed his account.

Castiel was going to have so much fun with his little kitten.


	2. Chapter 2

**Notes for the Chapter:**

> WARNING!! Chapter two includes castration as a kink. Chapter one doesn’t even mention it, and it stands alone, so you can read just the first chapter if that’s not your jam. [Click here if you’re new to castration kink and want to read my write up explaining it.](http://omegadeanlovesalphacas.tumblr.com/castrationkink)

Castiel was spoiling his kitten rotten. He couldn’t help it, he just loved the look on Dean’s face when he got a new toy or treat. He’d also bought him some things that were more for the alpha’s benefit, including faux fur gloves that matched his ears and tail, as well as knee pads. This allowed Dean to stay on his hands and knees outside, which Castiel much preferred.

Today he was taking Dean for his very first training class at OmegaPaws, and he was very excited. But before they went inside the shop he couldn’t help but pose Dean in front of the store, he just looked so cute. He always sat like a perfect kitten, with his hands on the ground between his folded knees, spread wide to show off his caged cock and the tail plug hanging between his legs.

Castiel took a bunch of pictures before choosing the best one where Dean looked the perfect mix of adorable and fuckable.

> Kitten’s first training class! If he’s good I’ll buy him a treat! #andknothimup #cantgetenoughofmykitten #leashedkitten #cagedkitten #omegakitten #okitsofinstagram

After posting the picture he finally headed into the store, with Dean crawling along beside him, looking curiously around him. He’d been afraid Dean would think he was being returned, but the omega seemed to be comfortable and content at Castiel’s side.

They had a little time to kill, so Castiel browsed the isles for a little bit, picking out a few more toys for his kitten. A vibrating cock ring and a pack of toy mice, those would keep him busy for hours.

When it was finally time for class, Castiel led Dean over to the fenced in area where the trainings were conducted. They were greeted by a tall alpha female with a short bob of blond hair.

“Hello, welcome!” she said, taking the training voucher Castiel handed her. “My name is Autumn, so nice to have you, and so good to see little Dean again!” She leaned down a little to get a better look at Dean. “I love what you’ve done with him, he’s looking fantastic!”

“Thank you!” Castiel grinned, leading Dean over to join the small group of alphas and kittens. Including the two of them, there were five pairs in the class, and of the five kittens there were three males and two females.

“Okay everyone, gather round,” Autumn said, stepping into the middle of the ring. “What we’re going to start with today is the first step towards total orgasm control. Our eventual goal is that your kittens reach a point where they cannot come unless directly ordered, even if they’re being naughty and playing with themselves without permission.” She looked around the small group. “I’m happy to see the boy kittens are caged, but for this exercise I would like you to please free them.”

Castiel did as he was instructed and unlocked the cage, freeing it from Dean’s cock. It quickly sprung to half hardness in response to the freedom.

The teacher nodded her approval when everyone was ready. “Now, we’re going to do a basic edging exercise. Using their tail plugs and your fingers, bring them close to orgasm, but if you think they’re getting too close, give the leash a gentle yank and order ‘no come.’ ”

Each of the alphas took a seat in one of the available chairs, and with a little tail tug they each had their kittens’ backend facing them.

Dean arched his back and spread his legs, just like he always did. Castiel couldn’t help it, he flipped Dean’s tail up over his back and took a picture, saving it to post to Instagram later. Holding the leash in one hand, he reached out and gripped the base of the plug, starting to gently wiggle it around, aiming to press against Dean’s prostate.

Dean squirmed and let out a meow, pushing his ass up higher. Castiel grinned and brought his thumb around to tease at his kitten’s rim where it was clamped down around the plug. Dean’s little meows got needier and he arched his back more, grinding his hips back against the plug.

Castiel suddenly realized Dean’s little cock was fully hard, and he gently tugged on the leash, ordering, “No come!” But it was too late, the omega’s come was already painting the floor.

“Oh dear,” Autumn said, eyebrows raised. “You seem to have a very sensitive little kitten to have come so quickly.” She pondered Dean for a moment. “Have you considered having him fixed? It would make it harder for him to come and increase your control, but he’d still be just as needy. And it has the added benefit of stopping his growth, he’s so cute and little, it would be nice to keep him that way.”

Castiel nodded. “Yeah, I’ve been seriously considering it,” he said. “We actually have an appointment at your omega vet right after this, I’ll talk to them about it.”

Autumn smiled. “Very good, I think you’d be very happy with the results.”

* * *

The rest of class went a little easier, Dean only came without permission one other time, but Castiel was able to stop most of them. When they were done he replaced the cock cage and led Dean across the store to the attached clinic.

It was quite convenient that OmegaPaws had their own vet clinic, and Castiel saw no reason to look for a different vet. When he walked Dean into the front lobby he was pleased with how clean and welcoming it was.

Castiel walked up to the front counter, leash in hand. “Castiel, I have an appointment for Dean?”

The young man behind the counter smiled up at them. He was a blond, blue eyed beta, and seemed genuinely friendly. “Welcome! We’ve got a room ready, let’s go ahead and get you and your kitten back there.”

He led Castiel and Dean around the desk and into the second exam room. “The doctor will be in shortly,” he said, closing the door behind him.

Castiel sat down on one of the chair, and Dean sat down at his feet. He cuddled up close to the alpha, suddenly a little nervous. “It’s okay, kitten,” Castiel said with a smile, petting Dean’s hair. “Don’t worry.”

At that moment a rather burly beta man stepped through the door. “Hello, Castiel is it? I’m Dr. Lafitte,” he said, putting out a hand for Castiel to shake. “But please, call me Benny.”

Castiel smiled, shaking his hand. “Nice to meet you, Benny.”

“And this must be Dean,” Benny said, smiling down at the omega. “Let’s get him up on the exam table so I can take a look.”

Castiel easily lifted his little omega into his arms and set him down on the stainless steel table. He was glad his kitten had his gloves and knee pads to protect him from the cold surface.

“What a good looking kitten,” Benny said, running his hand down Dean’s back and patting him on the butt.

“Thank you,” Castiel said with a big smile. “I just bought him last week, I couldn’t be happier.”

Dean squirmed a little and looked to Castiel for reassurance, and the alpha moved to stand by his head so he could pet him, holding the leash tight incase he tried to get off the table. He knew the omega wouldn’t like what came next.

“It’s okay, little kitten,” Benny said, his voice calm and level. His hands moved over Dean’s body, checking him thoroughly. He looked at his eyes and ears, and inside his mouth. He had Castiel removed the cock cage so he could check for chafing. “Everything looks good so far, I need to remove his tail now.”

Dean squirmed as Benny gently tugged the tail plug out of his channel, and slick readily started to run down the inside of his legs, built up from all the teasing at class.

Benny just chuckled. “That’s always nice to see.” He then picked up a speculum and gently eased it into Dean’s channel, spreading open his hole. He pulled on a pair of gloves and pushed two fingers inside.

Dean let out a yowl that was clearly a mix of pleasure and discomfort, and Castiel did his best to sooth him. “It’s okay, kitten, you’re okay,” he said, scratching his fingers in Dean’s hair.

Dean let out little moans as the beta’s fingers probed at his insides, and his little cock jumped when the veterinarian found his prostate and gently massaged it, checking for irregularities.

“No come,” Castiel ordered sharply, tugging on the leash.

Dean continued to squirm and let out a plaintive meow, but he managed to hold his orgasm at bay.  

Benny finally finished his exam and pulled the speculum free, quickly replacing it with a thermometer plug, and Dean’s entrance quickly contracted around the base.

“Everything looks good,” he said, smiling as he pulled off the gloves and tossed them in the trash. The thermometer beeped and displayed the temperature on the base of the plug, and Benny paused to record it. “If you ever decide to breed him I think you will be very pleased, he’s built to carry a whole litter.”

Castiel smiled, happy to hear that. “I’d like to do that some day,” he said, imagining how cute Dean would look with a swollen belly. “But for now I just wanted to talk to you about getting him fixed.”

Benny nodded, putting down the chart. “It’s a good idea, and the sooner the better. I recommend all male kittens be neutered, it reduces behavior problems and keeps them petite.”

Castiel frowned a little. “My only concern is I don’t want him to lose his sex drive, I love how needy and desperate he is.”

Benny shook his head. “Oh don’t worry, neutered kittens are just as desperate to be knotted, maybe even more so. They still have the sex drive but it’s harder for them to come without an order, so you can keep them constantly begging if that’s what you want.”

Castiel grinned. “That sounds awesome. Okay, when can we have it done?”

“Today if you’d like,” Benny said. “It’s a very quick procedure, I can have him done in thirty minutes.”

Castiel nodded. “Let’s do it.”

* * *

Dean’s procedure went smoothly, and after two weeks he was healed up and his stitches were out. It was almost like it had never happened, Castiel wasn’t sure his kitten even knew the difference.

But Castiel certainly did. He fucking loved it.

Dean couldn’t wear the cock cage anymore, but he didn’t need it. His little cock was already starting to shrink and he didn’t get hard nearly as easy now that he was fixed. And _good lord_ did he look sexy from behind.

“Stay,” Castiel said, keeping Dean in place where he was, on hands and knees on the bed. He picked up his phone and moved around behind the omega, flipping his tail plug up to sit on the top of his ass and hang over the left side. A little seed from his last knot was escaping around the plug, tracing a line down the fading scar to the omega’s cock where it hung between his legs. Castiel took his time getting the perfect picture, then quickly posted it to Instagram.

> So happy I got my kitten fixed! So sexy! #dontworry #hesstillaneedyslut #neuteredomega #needykitten #omegakitten #okitsofinstagram

With a grin Castiel dropped the phone on the bedside table and flopped on the bed. He was still naked from his last round with Dean and saw no reason for clothes any time soon. “Okay, good kitten,” he said, releasing Dean from his stay position. “All done.”

Dean quickly scampered over to flop down next to Castiel, going right for the alpha’s cock, lapping at it with little kitten licks.

Castiel groaned through a grin. “I _just_ knotted you,” he laughed, but didn’t object. He let Dean tease at his cock, eagerly lapping at the little beads of pre-come that started to leak from the tip. “Kitten loves his milk.”

Castiel wasn’t complaining, this was exactly what he wanted, exactly why Dean was only allowed one orgasm per week. It was one hell of an orgasm, and in between his little kitten was constantly begging, just the way Castiel like him.

Dean just purred and continued to suckle from his alpha, looking up at Castiel with the pleased eyes of the proverbial cat that got the cream as he slowly brought the alpha back to full hardness.

Castiel groaned when Dean finally took his whole cock in his mouth and sucked the full length down his throat. The omega seemed to enjoy having his mouth knotted just as much as his ass. Castiel laced his fingers through Dean’s hair, gripping tight and starting to thrust, fucking gently down the back of his kittens throat, then faster.

Dean went still with submission, continuing to purr as his alpha fucked his face.

When Castiel finally came with his knot locked behind Dean’s teeth he collapsed back on the bed, his seed steadily spilling down his kitten’s throat.

Dean just cuddled up between the alpha’s legs and purred around the knot filling his mouth, content for the moment.

Castiel let out a long sigh and released the grip on Dean’s hair and started to gently pet him. “Good kitten,” he muttered, already half asleep in a haze of pleasure. “Good kitten.”

**Author's Note:**

> Thanks for reading, I hope you enjoyed it. :)
> 
> Visit me on Tumblr: [omegadeanlovesalphacas.tumblr.com/mobilemenu.](http://omegadeanlovesalphacas.tumblr.com/mobilemenu)
> 
> (If you happen to be an artist who wants to draw the Instagram posts I would LOVE YOU FOREVER. Just saying.)


End file.
